Use of tissue sealants and other biological materials is an important emerging surgical technique, well adapted for the operating room or field environments such as the doctor""s office or mobile medical units. Preferred sealants include fibrin sealants which are formed from blood plasma components and comprise, on the one hand, a first component containing fibrinogen and Factor XIII and, on the other hand, a second component which usually includes thrombin, and calcium ions, however, other formulations may exist. The fibrinogen is capable of a polymerizing and being cross-linked to form a solid fibrin clot when the components are mixed. The necessary additional factors to simulate relevant portions of the natural blood coagulation cascade are suitably distributed between the fibrinogen and thrombin components.
Depending upon the potency of the particular formulations employed, coagulation of the sealant may take place very rapidly, yielding a gel within perhaps 10 or 20 seconds. Though often very desirable for surgical reasons, such fast-acting properties present potential problems of fouling or clogging. These problems must be overcome in devising suitable applicators, methods of application, and devices suitable for filling said applicators.
U.S. Pat. No. 5,585,007, issued to Antanavich et al., whose disclosure and references are hereby incorporated herein by reference thereto, provides an extensive discussion of the literature relating to fibrinogen sealant preparation (column 1, line 20 to column 4, line 62) and applicators column 4 line 62 to column 5, line 14), as well as a bibliography, (columns 6-10) and is a helpful guide to the teachings of prior workers in the field.
Until May of 1998, when the FDA first approved such products, fibrin sealant was not commercially available in the US. Therefore, use of fibrin sealant was limited to supplies produced within a clinic, and not subject to FDA control. After FDA approval, however, fibrin sealant became commercially available in the US. This availability has created a need for an effective and efficient device useful for dispensing the components of the sealant from commercially available or standardized applicators to an area of interest in a controlled, efficient manner.
A popular manually operable applicator for such two-component sealants employs a dual syringe construction wherein two syringes, connected by a yoke, each provide a reservoir for one of the components. In most prior devices, the sealant components are discharged in separate streams and mixed externally of the applicator. Such applicators are similar in principle to household epoxy glue applicators commonly available in hardware stores. While the syringe-type applicators have proved beneficial when applying a multiple component sealant, use of these applicators occasionally resulted in fatigue of the operator""s hand.
Thus, there is a need for an easy to operate device capable of applying a multiple component fluid from a multi-syringe applicator to an area of interest.
The present invention solves the problem of effectively delivering multiple components directly from commercially available or standardized applicators, for example, multi-syringe applicators, to an area of interest. Additionally, the present invention provides increased dispensing control while enhancing operator comfort.
In one aspect, the present invention provides a multi-component applicator comprising a multi-syringe applicator and a handheld applicator adapted to functionally receive a multi-syringe applicator and dispense material stored in the multi-syringe applicator.
The multi-syringe applicator has a first syringe container and a second syringe container. The first syringe container, storing a first component, comprises a first syringe piston, a portion of which is slidably positioned within the first syringe container, a first piston rod attached thereto, and a first syringe pusher attached to the first piston rod. Likewise, the second syringe container, storing a second component, comprises a second piston, a portion of which is slidably positioned within the second syringe container, a second piston rod attached thereto, and a second syringe pusher attached to the second piston rod.
The handheld applicator comprises an applicator housing having an elongated body portion, a stationary handle portion, and a moveable trigger device. Located within the applicator housing is an applicator cavity containing an engagement member and a movement actuator. The engagement member and the movement actuator functionally couple the motion of the moveable trigger device to the dispensing action of the handheld applicator.
Also positioned within the applicator cavity is a return stop and a dispensing stop. These stops regulate the amount of force applied by the handheld applicator to the multi-syringe applicator. It has been shown that multi-syringe applicators have an optimal range of force that may be applied to the syringes to achieve the desired dispensing effect. Normally, the application of insufficient force by the handheld applicator results in the components being dispensed in inadequate or uneven flowrates, or the material being dispensed in a liquid stream. The application of excessive force by the handheld applicator results in insufficient component mixing, and may, in extreme cases, result in failure of the multi-syringe applicator, or the handheld applicator, or both. The present invention addresses and solves this problem by utilizing a return stop and a dispensing stop. The return stop limits the stroke length of the moveable trigger device by providing a physical stop which contacts the moveable trigger device and limits the obtainable sweep length of the moveable trigger device with regard to the stationary handle. The dispensing stop limits the amount the engagement device will advance during each operational cycle. The return stop and dispensing stop effectively regulate the mechanical advantage the handheld applicator may apply to the multi-syringe applicator during one operational cycle.
The distal portion of the handheld applicator may be capable of receiving a plurality of dispensing tips. For example, in one embodiment the distal portion of the handheld applicator may dispose a detachable spray tip, which mixes and atomizes the various components just prior to application. The present invention may dispense the material in a plurality of manners, including, without limitation, liquid stream form and spray form.
In an additional embodiment of the present invention, a force dampener is positioned at the interface between the handheld applicator and the multi-syringe applicator. The force dampener prevents damage to the multi-syringe applicator and provides an additional force limiting function.
Other objects and further features of the present invention will become apparent from the following detailed description when read in conjunction with the attached drawings.